Dilation system

Abstract

A dilation system for accessing a surgical target site to perform surgical procedures. In one version, the dilation system includes a wedge assembly and an actuating mechanism. The wedge assembly comprises includes a base and a plurality of blades extending from the base so that the distal end of the blades extend away from the base. The mechanism is operably associated with the blades so as to cause the distal end of the blades to move from a closed condition to an expanded condition.

What is claimed is: 
     
       1. A dilation system, comprising:
 a wedge assembly, comprising:
 a base; 
 a first blade having a proximal end, a distal end, an arcuate outer surface, an inner surface, and longitudinal edges extending from the proximal end of the first blade to the distal end of the first blade, the first blade extending from the base so that the distal end of the first blade extends away from the base member; and 
 a second blade having a proximal end, a distal end, an arcuate outer surface, an inner surface, and longitudinal edges extending from the proximal end of the second blade to the distal end of the second blade, the second blade extending from the base so that the distal end of the second blade extends away from the base; and 
 
 an actuating mechanism operably associated with the first blade and the second blade so as to cause the distal end of the first blade and the distal end of the second blade to move from a closed condition to an expanded condition, 
 wherein the longitudinal edges of the first blade and the longitudinal edges of the second blade form a gap when the first blade and the second blade are in the expanded condition, 
 wherein the actuating mechanism comprises a drive member having a proximal end and a distal end, the drive member slidably positioned between the first blade and the second blade and configured so axial movement of the drive member moves the first blade and the second blade from the closed condition to the expanded condition, 
 wherein the drive member is configured in such a way that the drive member extends between the first blade and the second blade to fill the gap between the longitudinal edges of the first blade and the longitudinal edges of the second blade when the first blade and the second blade are in the expanded condition, 
 wherein in the closed condition the outer surfaces of the first blade and the second blade are in a tapering relationship relative one another from the proximal ends of the first blade and the second blade to the distal ends of the first blade and the second blade so the outer surfaces of the first blade and the second blade cooperate with one another to form an oblong transverse profile, in the expanded condition the distal ends of the first blade and the second blade are spread apart relative to the position of the distal ends of the first blade and the second blade when in the closed position so the outer surfaces of the first blade and the second blade cooperate with the drive member to form a substantially circular transverse profile. 
 
     
     
       2. The dilation system of  claim 1 , wherein the drive member has a proximal base, a distal base, a first blade extending between the proximal base and the distal base, a second blade extending between the proximal base and the distal base in a spaced apart, parallel relationship to the first blade so that the first blade and the second blade of the drive member are slidably positionable between the first blade and the second blade of the wedge assembly. 
     
     
       3. The dilation system of  claim 2 , wherein the first blade of the drive member has longitudinal edges extending from the proximal base to the distal base, wherein the second blade of the drive member has longitudinal edges extending from the proximal base to the distal base, and wherein the longitudinal edges of the first blade and the second blade of the drive member are configured to mate with the longitudinal edges of the first blade and the second blade of the wedge assembly so that the outer surfaces of the first blade and the second blade of the drive member are flush with the outer surfaces of the first blade and the second blade of the wedge assembly in the expanded condition. 
     
     
       4. The dilation system of  claim 2 , wherein at least one of the first blade and the second blade of the wedge assembly has a longitudinal slot formed in an outer surface thereof for receiving a stimulating probe, and wherein the proximal base of the drive member is generally U-shaped to provide an open side corresponding with the longitudinal slot of the wedge assembly. 
     
     
       5. The dilation system of  claim 2 , wherein the distal base of the drive member is configured to slidingly mate with the inner surface of the first and second blades of the wedge assembly to cause the first and second blades of the wedge assembly to move from the closed condition to the expanded condition when the distal base is caused to be moved axially from the proximal ends of the first and second blades of the wedge assembly to the distal ends of the first and second blades of the wedge assembly. 
     
     
       6. The dilation system of  claim 5 , wherein the distal base is provided with an open sided hole for supporting and guiding the stimulating the probe. 
     
     
       7. The dilation system of  claim 2 , wherein the base of the wedge assembly has a central tubular portion sized to receive a stimulating probe, and wherein the distal end of the first blade and the distal end of the second blade of the wedge assembly has a notch cooperating to define an opening sized to receive the stimulating probe when the first blade and the second blade of the wedge assembly are in the closed condition.